Lectins and applications for the detection of pathological state markers

Abstract

Multimenic lectins having a β-propeller architecture, formed from monomer modules of approximately 30 to 60 amino acids, in which the binding sites to the glycans are situated on a given side of the proteins and the O-terminus and N-terminus ends of the peptide chains on the other side of the proteins, characterized in that they are formed from 4 to 7 monomer modules, a single, or a plurality of, or all of the adjacent modules being linked to one another by the linkers linking the N-terminus end of one module to the C-terminus end of the adjacent module.

The invention claimed is: 
     
       1. A monomeric, single polypeptide chain lectin having a β-propeller architecture, said lectin comprising 4 to 7 peptide modules,
 wherein each module comprises about 30 to 60 amino acids; 
 wherein each module comprises a glycan binding site; 
 wherein at least one glycan binding site comprises at least one mutation, said mutation altering glycan binding; 
 wherein each module is linked to another module with a peptide linker; and 
 wherein at least one peptide linker is an exogenous peptide linker. 
 
     
     
       2. The lectin of  claim 1 , wherein the peptide linkers are the same or different, wherein the peptide linkers comprises 2 to 10 amino acids. 
     
     
       3. The lectin of  claim 1 , wherein the lectin is multivalent and capable of binding more than one glycan or the lectin is monovalent and binds a single glycan. 
     
     
       4. The lectin of  claim 1 , wherein the lectins comprises one or more lysine functional groups, wherein the lysine functional groups comprise a label. 
     
     
       5. The lectin of  claim 4 , wherein said label is a fluorophore or biotin. 
     
     
       6. The lectin of  claim 1 , wherein the peptide modules are derived from RSL ( Ralstonia solanacearum  lectin), BambBL ( Burkholderia ambifaria  lectin), BC2LL-nt ( Burkholderia cenocepacia  lectin), HPA ( Helix pomatia  lectin), discoidin ( Dictyostelium discoideum  lectin), CTX-B (cholera toxin lectin) lectins, B5 type bacterial toxins, AAA ( Anguilla anguilla  lectin), and adenovirus lectin. 
     
     
       7. A method for producing the monomeric, single polypeptide chain lectin of  claim 1 , said method comprising:
 transforming a host cell with nucleic acid encoding the monomeric, single chain lectin, 
 culturing said host cell in culture medium under conditions for the expression of the monomeric, single polypeptide chain lectin, 
 isolating the monomeric, single polypeptide chain lectin from the host cells or the culture medium. 
 
     
     
       8. A method for identifying glycosylation epitopes on a cell surface in vitro, said method comprising:
 contacting cells with the lectin of  claim 1 , 
 wherein the glycosylation epitopes are identified when the lectin binds to the cell surface glycan.